TIMESYNCD.CONF(5) timesyncd.conf TIMESYNCD.CONF(5)
NAME
timesyncd.conf, timesyncd.conf.d - Network Time Synchronization
configuration files
SYNOPSIS
/etc/systemd/timesyncd.conf
/etc/systemd/timesyncd.conf.d/*.conf
/run/systemd/timesyncd.conf.d/*.conf
/usr/lib/systemd/timesyncd.conf.d/*.conf
DESCRIPTION
These configuration files control NTP network time synchronization. See
systemd.syntax(5) for a general description of the syntax.
CONFIGURATION DIRECTORIES AND PRECEDENCE
The default configuration is defined during compilation, so a
configuration file is only needed when it is necessary to deviate from
those defaults. By default, the configuration file in /etc/systemd/
contains commented out entries showing the defaults as a guide to the
administrator. This file can be edited to create local overrides.
When packages need to customize the configuration, they can install
configuration snippets in /usr/lib/systemd/*.conf.d/. Files in /etc/
are reserved for the local administrator, who may use this logic to
override the configuration files installed by vendor packages. The main
configuration file is read before any of the configuration directories,
and has the lowest precedence; entries in a file in any configuration
directory override entries in the single configuration file. Files in
the *.conf.d/ configuration subdirectories are sorted by their filename
in lexicographic order, regardless of which of the subdirectories they
reside in. When multiple files specify the same option, for options
which accept just a single value, the entry in the file with the
lexicographically latest name takes precedence. For options which
accept a list of values, entries are collected as they occur in files
sorted lexicographically. It is recommended to prefix all filenames in
those subdirectories with a two-digit number and a dash, to simplify
the ordering of the files.
To disable a configuration file supplied by the vendor, the recommended
way is to place a symlink to /dev/null in the configuration directory
in /etc/, with the same filename as the vendor configuration file.
OPTIONS
The following settings are configured in the "[Time]" section:
NTP=
A space-separated list of NTP server host names or IP addresses.
During runtime this list is combined with any per-interface NTP
servers acquired from systemd-networkd.service(8).
systemd-timesyncd will contact all configured system or
per-interface servers in turn until one is found that responds.
When the empty string is assigned, the list of NTP servers is
reset, and all assignments prior to this one will have no effect.
This setting defaults to an empty list.
FallbackNTP=
A space-separated list of NTP server host names or IP addresses to
be used as the fallback NTP servers. Any per-interface NTP servers
obtained from systemd-networkd.service(8) take precedence over this
setting, as do any servers set via NTP= above. This setting is
hence only used if no other NTP server information is known. When
the empty string is assigned, the list of NTP servers is reset, and
all assignments prior to this one will have no effect. If this
option is not given, a compiled-in list of NTP servers is used
instead.
RootDistanceMaxSec=
Maximum acceptable root distance. Takes a time value (in seconds).
Defaults to 5 seconds.
PollIntervalMinSec=, PollIntervalMaxSec=
The minimum and maximum poll intervals for NTP messages. Each
setting takes a time value (in seconds). PollIntervalMinSec= must
not be smaller than 16 seconds. PollIntervalMaxSec= must be larger
than PollIntervalMinSec=. PollIntervalMinSec= defaults to 32
seconds, and PollIntervalMaxSec= defaults to 2048 seconds.
SEE ALSO
systemd(1), systemd-timesyncd.service(8), systemd-networkd.service(8)
systemd 241 TIMESYNCD.CONF(5)
